The present invention relates generally to automotive vehicle seating and, more particularly, to a seat slide device of the type used in manually-operated seat adjustment mechanisms.
Virtually all modern motor vehicles are equipped with seating systems that can be selectively adjusted for providing increased comfort and convenience to the seat occupants. In many manually-actuated systems, the seat is supported for movement on a seat adjustment mechanism that can be selectively actuated for permitting the seat occupant to adjust the horizontal (i.e., "fore" and "aft") position of the seat. Typically, the seat adjustment mechanism includes a pair of laterally-spaced seat slide devices each having a lower track fixed to the vehicle's floor structure, an upper track fixed to the seat and which is supported for sliding movement on the lower track, and a manually-operable latching mechanism for releasably latching the upper track (and seat) in the desired adjusted position relative to the lower track. In addition, a common handle or linkage assembly is also generally provided for causing synchronous actuation of each of the latching mechanisms associated with the laterally-spaced seat slide devices to inhibit lateral (i.e., side-to-side) misalignment of the seat.
Commonly, the latching mechanisms incorporated into conventional seat slide devices include a lock plate attached to the stationary lower track and a latch plate supported from the upper track for pivotable movement between a "locked" position of engagement with the lock plate and a "released" position of disengagement therewith. Typically, a plurality of locking projections (i.e., teeth, hooks, tabs, etc.) are formed on one of the latch plate and the lock plate for interdigitated engagement with a series of locking apertures formed on the other of the plates in response to movement of the latch plate to the "locked" position. The manually-operable handle assembly permits the seat occupant to pivot the latch plate to the "released" position when it is desired to adjust the horizontal position of the seat. In addition, the latching mechanisms are spring-biased for normally urging the latch plate toward the "locked" position.
In an effort to inhihit separation (i.e., "peeling") of the upper track from the lower track during collisions and other heavily-loaded conditions, it is known to structurally "interlock" the upper track on the lower track. Such an arrangement is disclosed in U.S. Pat. No. 4,957,267 to Terai wherein the inwardly-turned vertical flanges formed on the opposite lateral edges of the upper track are nested within longitudinal channels formed by outwardly-turned vertical flanges on the lower track. To permit sliding movement and minimize lateral "play", a plurality of balls are rotatably disposed above the longitudinal channels and between a horizontal surface portion of the upper track and a horizontal portion of the outwardly-turned flanges on the lower track. A similar interlocking track arrangement is shown in U.S. Pat. No. 4,487,459 to Rees with the exception that plastic slides are substituted for the balls. However, while most conventional seat slide devices work satisfactory for their intended purpose, they are typically complex in design and construction and expensive to manufacture.